摘要:
``` CSS
-webkit-filter: grayscale(100%);
-moz-filter: grayscale(100%);
-ms-filter: grayscale(100%);
-o-filter: grayscale(100%);
filter: grayscale(100%);
filter: gray;
``` 阅读全文
摘要:
```css
top: 0px;
bottom: 0px;
left: 0px;
right: 0px;
margin-left: auto;
margin-right: auto;
``` 阅读全文